Journal of the Korea Institute of Information and Communication Engineering (한국정보통신학회논문지)

The Korea Institute of Information and Commucation Engineering (한국정보통신학회)
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A Channel Estimation Method by Orthogonalizing of the time domain training signals in MIMO-OFDM systems

MIMO-OFDM 시스템에서 시간영역 훈련신호들의 직교화를 통한채널추정 방법

  • Jeon, Hyoung-Goo (Department of Information Communication Engineering, Dong-Eui University)
  • Received : 2013.10.29
  • Accepted : 2013.11.29
  • Published : 2013.12.31
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Abstract

In this paper, a channel estimation method by orthogonalizing of the time domain training signal in MIMO-OFDM systems is proposed. It has shown that Jeon's method[8] cannot be directly used in 4 Tx antenna MIMO-OFDM systems since the delayed Rx signals interfere the orthogonal property of the time domain training signals. As a possible solution to the problem, in this paper, a guard interval is inserted into the center of the training signals so that the orthogonal property between the Rx training signals can be maintained. It is shown by using computer simulations that the proposed method can estimate the channel response in time domain in 4 Tx antenna MIMO-OFDM systems.

본 논문에서는 MIMO-OFDM 시스템에서 시간영역 훈련신호의 직교화를 통한 채널추정 방법을 제안하였다. 본 논문에서는 Jeon[8]이 제안한 방법을 그대로 송신 안테나 개수가 4개인 MIMO-OFDM 시스템으로 확장하였을 때 수신기에서 다중경로 지연신호로 인하여 훈련신호가 직교되는 않는 문제점이 있음을 보였다. 이러한 문제점에 대한 해결책으로 훈련신호 중앙에 보호구간을 삽입하는 새로운 훈련신호 발생 방법을 제안하였다. 제안한 방법은 훈련신호들이 서로 직교하기 때문에 수신기에서 Walsh decoding sum기법을 통하여 시간영역에서 채널응답을 추정할 수 있음을 보였다.

Keywords

References

  1. Y. Sun, "Bandwidth efficient wireless OFDM," IEEE Journal Selected Areas on Communication," Vol. 19, No. 11, pp 2267-2278, Nov. 2001. https://doi.org/10.1109/49.963812
  2. IEEE 802.16 "Part 16: Air Interface for Fixed Broadband Wireless Access Systems - Medium Access Control (MAC) Modification and Additional Physical Layer(PHY) Specification for 2-11 GHz," P802.16a/D7, Nov. 2002.
  3. John Terry and Juha Heiskala, OFDM Wireless LANs: ATheoreticaland PracticalGuide, SamsPublishing,2002.
  4. Y. (G.) Li, N. Seshadri, and S. Ariyavisitakul, "Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels," IEEE J. Selected Area Comm., Vol. 17, pp. 461-471, March 1999. https://doi.org/10.1109/49.753731
  5. Y. (G.) Li, "Simplified channel estimation for OFDM systems with transmit antenna," IEEE Trans. On Comm., Vol. 1, pp. 67-75, January 2002.
  6. Yi Gong, Letaief, K.B., "Low complexity channel estimation for space-time coded widehand OFDM systems," IEEE Transactions on Wireless Comm., Vol. 2, pp. 876-882 Sept. 2003. https://doi.org/10.1109/TWC.2003.816797
  7. Jianxin Guo, Daming Wang, Chongsen Ran, "Simple channel estimator for STBC-based OFDM systems," Electronics Letters, Vol. 39, pp. 445-447 March 2003. https://doi.org/10.1049/el:20030284
  8. Hyoung-Goo Jeon, Hyoung-Kyu Song, and Erchin Serpedin, "Walsh coded Training signal Aided Time domain Channel Estimation for MIMO-OFDM systems, " IEEE Transaction on communications, Vol. 56, No. 9, pp.1430-1433, Sept. 2008. https://doi.org/10.1109/TCOMM.2008.060402
  9. S. H. Muller and J. B. Huber, "A comparison of peak power reduction schemes for OFDM," Global Telecommunications conference, Vol. 1, pp. 1-5, Nov. 1997.
  10. H. Hara and R. Prasad, Simulation and Software Radio for Mobile Communications, Artech House, 2002.
  11. Y. Teng, K. Mori, and H. Kobayashi, "Performance of DCT Interpolation based Channel Estimation for MIMO-OFDM systems," in Proc. ISCIT2004, Vol. 2, pp. 622-627, Oct. 2004.